This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A253601 #9 Aug 07 2018 07:09:57
%S A253601 4,9,17,18,24,29,33,34,38,39,44,54,57,58,59,62,67,72,79,84,88,94,144,
%T A253601 158,173,194,209,212,224,237,238,244,247,253,257,259,307,313,314,333,
%U A253601 334,338,349,353,359,377,388,404,409,424,437,444,447,449,454,459,467
%N A253601 Numbers such that the smallest exponent for n and n^k to have common digits is 3.
%H A253601 Iain Fox, <a href="/A253601/b253601.txt">Table of n, a(n) for n = 1..10000</a>
%e A253601 4^2=16 has no digits in common with 4, but 4^3=64 has some, so 4 is in the sequence.
%o A253601 (PARI) a253600(n) = {sd = Set(vecsort(digits(n))); k=2; while (#setintersect(sd, Set(vecsort(digits(n^k)))) == 0, k++); k;}
%o A253601 isok(n) = a253600(n) == 3;
%o A253601 (PARI) is(n) = my(d(k)=Set(digits(n^k))); !#setintersect(d(1), d(2)) && #setintersect(d(1), d(3)) \\ _Iain Fox_, Aug 07 2018
%Y A253601 Cf. A103173, A189056, A253600, A253602.
%K A253601 nonn,base
%O A253601 1,1
%A A253601 _Michel Marcus_, Jan 05 2015